08-25-2022, 03:01 AM | #1 |
Drives: 2019 SS 1987 GN 1972 442 Join Date: Aug 2022
Location: IL
Posts: 10
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Muffler delete issue
Hi, I have a 19 SS all stock, except i just had a muffler shop delete my muffler and the 4 npp valves . Sounds great, but after 21 miles of driving the check engine light came on. The electronic portion of the valves were unbolted and ziptied out of harms way, and are still plugged in. (Code P12ea) Maybe I need to unplug them to make the
light go away? Ive heard everyone on here say that should not turn cel on. I try to clear code but it stays on. Please advise Last edited by smokingv6; 09-04-2022 at 11:52 AM. |
08-25-2022, 06:27 AM | #2 |
Drives: 23 ZL1 A10 Rapid Blue Join Date: Aug 2020
Location: MO
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There are 2 NPP valves, it sounds like they pulled the AFM valve's in the midpipe which you cannot do w/o throwing codes.
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08-26-2022, 07:47 AM | #3 |
Hot Camaro
Drives: '20 2SS Convertible 6MT Join Date: May 2020
Location: CT
Posts: 3,541
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Yep. The two that are partway through the exhaust and NOT connected to the muffler are required for the AFM to work correctly. Either those need to go back on, or AFM now has to be tuned out. Additionally, the valves need to be wired to the harness, still, or the car will throw codes for other reasons.
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08-26-2022, 09:35 AM | #4 |
Drives: 2016 Camaro 1LT Join Date: Jan 2016
Location: California
Posts: 3,493
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08-26-2022, 09:41 AM | #5 |
Hot Camaro
Drives: '20 2SS Convertible 6MT Join Date: May 2020
Location: CT
Posts: 3,541
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08-26-2022, 09:44 AM | #6 |
Drives: 2016 Camaro 1LT Join Date: Jan 2016
Location: California
Posts: 3,493
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08-26-2022, 07:40 PM | #7 |
Drives: 2019 SS 1987 GN 1972 442 Join Date: Aug 2022
Location: IL
Posts: 10
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Thanks for all the responses. I may get those 2 put back on. They seem like they don't restrict a whole lot compared to the almost flat sections that I removed due to clearing the extra bars for my convertible. At the same time, I will also add electric cutouts right before the secondary converters. Noise is not an issue with me or my neighbors .
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08-26-2022, 07:44 PM | #8 |
Drives: 2019 SS 1987 GN 1972 442 Join Date: Aug 2022
Location: IL
Posts: 10
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08-26-2022, 09:08 PM | #9 | |
Drives: 2016 2SS Convertible Join Date: May 2012
Location: St. Louis, MO
Posts: 1,730
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Quote:
https://www.awe-tuning.com/news/awe-...d-c7-corvette/ |
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08-26-2022, 09:27 PM | #10 |
Hot Camaro
Drives: '20 2SS Convertible 6MT Join Date: May 2020
Location: CT
Posts: 3,541
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When the ECU is dropping the motor down to 4CYL mode, those get closed to create additional back pressure. If they are removed, the computer will throw codes due to lack of back pressure in 4CYL mode.
The flat sections of the exhaust create no appreciable difference in the back pressure that affects how the motor runs. |
09-04-2022, 11:50 AM | #11 | |
Drives: 2019 SS 1987 GN 1972 442 Join Date: Aug 2022
Location: IL
Posts: 10
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Quote:
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09-05-2022, 06:03 PM | #12 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
Posts: 2,344
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You need the simulators that bolt on to the electric motors that are ziptied to the underside of the car. Cut the zipties, bolt on the simulators and re ziptie to the undercarriage.
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09-05-2022, 11:36 PM | #13 |
Drives: 2019 SS 1987 GN 1972 442 Join Date: Aug 2022
Location: IL
Posts: 10
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[QUOTE=lt4camaro;11224901]You need the simulators that bolt on to the electric motors that are ziptied to the underside of the car. Cut the zipties, bolt on the simulators and re ziptie to the undercarriage.[/QUO
I did that, seems to be fine so far.... |
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